When you need to explain why something is the way it is or why you did something, Japanese has three incredibly useful grammar patterns. Mastering these will significantly improve your conversation skills, as you’ll be able to communicate reasons clearly.
Simple Reason: Particle 「から」 (kara)
The particle 「から」 is the simplest way to express a reason. It translates most closely to “because” or “since.” It is always placed immediately after a full sentence (in either short form or polite form).
The structure is: [Reason/Cause] から、[Result/Action]
Rule: The sentence before から can be in the polite form (〜ます/です) or the short form.
Examples
- 日本語は難しいですから、毎日勉強します。Nihongo wa muzukashii desu kara, mainichi benkyou shimasu.Because Japanese is difficult, I study every day.
- お金がないから、パーティーに行きません。Okane ga nai kara, paatii ni ikimasen.Since I don’t have money, I won’t go to the party.
2. Softer Reason: Particle 「ので」 (node)
The particle 「ので」 also means “because” or “since,” but it sounds slightly softer, more like “given that…” or “since…” It is often used to give a reason that justifies a request or action without sounding too demanding.
The structure is: [Reason/Cause] ので、[Result/Action]
Rule: The sentence beforeので must be in the short form (plain form).
Exception for な-adjectives and nouns: You must add な before ので. (e.g., 静かなので shizuka na node)
Examples:
- 道が混んでいるので、遅れます。Michi ga konde iru node, okuremasu.Since the road is crowded, I will be late.
- 今日は暇(ひま) なので、一緒に映画を見ましょう。Kyou wa hima na node, issho ni eiga o mimashou.Since I am free today, let’s watch a movie together. (Note: な-adjective + な + ので)
3. Seeking or Providing Explanation: 「んです」 (n desu)
The phrase 「んです」 (or the more polite 「のです」 – no desu) is an explanatory form. It’s used to:
- Ask for an explanation: Asking why in a way that suggests you’re seeking background information.
- Give an explanation: Providing the reason or background context for a previous statement or situation.
The structure is: [Sentence in Short Form] んです
Rule: The sentence before んです must be in the short form.
Examples (Asking for an Explanation):
- どうして 日本語を勉強している んですか。Doushite Nihongo o benkyou shite iru n desu ka.Why are you studying Japanese? (I’m curious about the reason.)
Examples (Providing an Explanation):
- A: 顔色が悪いですよ。 (
Kaoloroi ga warui desu yo.) – Your complexion is bad. - B: 昨日、寝なかった んです。 (
Kinou, nenakatta n desu.)(The reason is that) I didn’t sleep yesterday. - A: 寿司を頼まないんですか。 (
Sushi o tanomanai n desu ka.) – Aren’t you going to order sushi? - B: 私は魚が嫌い なんです。 (
Watashi wa sakana ga kirai nan desu.)(The reason is that) I dislike fish. (Note: な-adjective/Noun + な + んです)
By using から for a direct reason, ので for a softer one, and んです to ask for or provide an explanation, you can communicate the “why” behind any situation in Japanese!